---
title: fieldBitMask
framework: spritekit
role: symbol
role_heading: Instance Property
path: spritekit/skphysicsbody/fieldbitmask
---

# fieldBitMask

A mask that defines which categories of physics fields can exert forces on this physics body.

## Declaration

```swift
var fieldBitMask: UInt32 { get set }
```

## Discussion

Discussion When a physics body is inside the region of an SKFieldNode object, that field node’s categoryBitMask property is compared to this physics body’s fieldBitMask property by performing a logical AND operation. If the result is a nonzero value, the field node’s effect is applied to the physics body. The default value is 0xFFFFFFFF (all bits set).

## See Also

### Interacting with Physics Fields

- [charge](spritekit/skphysicsbody/charge.md)